1. FIELD OF USE
The present invention is in the field of medical devices which deliver radio-frequency energy to cut tissue. More specifically, the invention is in the field of cutting probes for arthroscopic surgery.
2. BACKGROUND
Arthroscopic surgery is becoming increasingly popular, because it generally does less damage than open procedures, produces less scarring in and around joints, and results in faster healing and return of the patient to full productivity.
Nevertheless, arthroscopic surgery has its limitations. The surgeon must operate through a narrow tube, which is awkward. Only one probe can be used at a time. Often the viewing camera is positioned at an angle different from the surgeon's normal gaze. This contrasts with "open surgery" where the surgeon has relative ease of viewing the surgical site and can freely move both hands, even utilizing the hands of colleagues.
In view of such difficulties of arthroscopic surgery, it is understandable that laser, microwave and radio-frequency (RF) probes which simultaneously cut and coagulate are preferred. However, current probes are poorly adapted to certain activities, such as cutting narrow tendons or ligaments. Current probes have convex, pointed and/or flat tips. U.S. Pat. No. 5,308,311, issued May 3, 1994 to Eggers and Shaw, is exemplary in that it discloses a laser probe with a pointed tip and convex side. With current probes, the surgeon has little control when pressing against a tough ligament. Now as the surgeon cuts through one portion of the ligament, the probe slips out of position. The surgeon must reapproximate the probe and cut again, an inefficient process. And, unless the surgeon is able to stop pressure at exactly the right time, the probe may slip and cut an adjacent structure. Because the surgeon must repeatedly reapproximate and cut the ligament, the surgeon has difficulty in cleanly ablating the ligament or tendon. Thus, there are certain procedures that surgeons still prefer to perform in the "open." Unfortunately, this often results in bigger scars, longer convalescence, and more irritation of an already irritated joint.
What is needed is a probe that can simultaneously direct the tendon to the energy source (e.g., RF) and apply RF to cleanly and smoothly ablate the tendon or ligament. The advantage is that some procedures that have been considered too awkward or difficult to perform by arthroscopy can now be performed more effectively by arthroscopy.